沱江流域内江段不同土壤有机碳含量研究

RESEARCH ON THE INFLUENCE FACTORS OF SOIL ORGANIC CARBON IN NEIJIANG SECTION OF TUOJIANG RIVER BASIN

针对沱江流域内江沱江乡,在野外调查、土壤样品采集与室内测试的基础上,通过相关软件统计分析剖析了沱江流域内江段农田土壤有机碳分布特征。结果表明:研究区侏罗系沙溪庙组四段土壤有机碳的含量高于侏罗系沙溪庙组三段。以第四系成因来看,土壤有机碳分布规律按大小顺序为:残坡积物、残积物、坡洪积物、冲积物。从不同土壤有机碳含量差异性来看,水稻土有机碳含量高于紫色土。在不同土地利用方式下,土壤有机碳含量的多寡分布按大小顺序为:灌溉水田、荒地、林地、旱地;水田土壤有机碳含量高于旱地,水田的潜在固碳量大于旱地。由于农田土壤固碳过程受诸多因素共同作用,因此准确认识和辨别其主要影响因子成为了精确评估土壤有机碳变化方向及速率的关键问题。

Combining field investigations and laboratory analysis,this paper studied on the influence factors of farmland soil organic carbon(SOC) in Neijing section of Tuojiang River Basin through the relevant statistical software.The results indicate that the SOC in the forth section of Jurassic Shaximiao Formation is higher than that of the third section.Different cause of Quaternary system considered,the regularities of distribution in order of increasing size would be:Qeld、Qel、Qdpl、Qal.The four items successively stands for residual sediments,eluvium,slope diluvium and drift.Considering different land type,the result would be that the organic carbon content is higher in paddy soils than in purple soil.Under different utilization pattern of soil,the amount of SOC is in the order of size:paddy fields、wasteland、woodland、dry land.The changes of soil organic carbon content is as follows:irrigation paddy、woodland、dry land、wasteland.It shows that the paddy field soil organic carbon content is higher than dry land and also has a greater potential of carbon sequestration.Soil carbon sequestration is complex cause that affected by a number of factors,and how to correctly understand and distinguish the main influencing factor is a key scientific issues to assess the direction and rate of the change of soil organic carbon.